Printing cylinder vacuum control



July 26, 1955 E. A. LUSCOMBE 2,713,823

PRINTING CYLINDER VACUUM CONTROL Filed Nov. 25, 1949 2 Sheets-Sheet l IN V EN TOR.

by'dgdr'lq. L uscombe B July 26, 1955 E. A. LUSCOMBE PRINTING CYLINDER VACUUM CONTROL 2 Sheets-Sheet 2 Filed Nov. 25, 1949 Unite States Patent FRINTING CYLINDER VACUUM CONTROL Edgar A. Luscombe, La Grange, Ill., assignor to Miehle Printing Press and Manufacturing Company, Chicago,

This invention relates to vacuum controls for use on sheet fed printing presses and other classes of machinery. It more particularly pertains to improvements in the sheet controlling means such as are associated with the impression cylinders of such presses.

While my invention is disclosed herein preferably as being applied in connection with a conventional Vertical printing press in which the type bed and impression cylinder have relative vertical reciprocatory motion, its utility is not limited to such machinery because it may be used to advantage in any class of machines which involve air controlled mechanism for feeding material thereto.

In the operation of printing presses for example, it is common practice to employ vacuum controlled sheet detecting means associated with the sheet carrying cylinder which means function to trip the cylinder or the press either when a sheet does not reach the cylinder, is not presented to it in proper timed sequence, or if the sheet is not in register with the front registering guides on the cylinder.

In presses of the type set forth herein, it has been the usual procedure to employ a flexible rubber tube for the purpose of connecting the vacuum controlled elements on the reciprocating cylinder mounting to the stationary main vacuum line of the press. Because of the constant flexing of such tube when the press is in operation, the usefulness of the tube proved to be quite limited and frequent replacements were necessary.

Furthermore, because of the fact that the vacuum line was directed through the cylinder journal box which journal must be lubricated constantly with a liberal supply of oil, it was difiicult, if not impossible, to prevent leakage of oil into the air system of the press, with the result that oil would eventually reach the printed sheets and thereby spoil them.

Moreover, the effectiveness of the vacuum was directly dependent on the accuracy and snug fit of the journal in its bearing box, which parts, however, would eventually wear sufficiently to result in leakage of air and consequent destruction of the vacuum.

It is, therefore, one of the primary objects of my invention to provide a simple, reliable and eflicient mechanism whereby defects such as I have indicated herein, shall be eliminated. Another object of the invention is the provision of means having a. fixed position with respect to the impression cylinder, whereby the vacuum elements on the cylinder shall be connected to the main vacuum line of the press in proper timed relation.

A further object of my invention is to provide means for connecting the main vacuum line to the elements on the cylinder in a manner that any seepage of oil to the vacuum line shall be avoided.

. A still further object of this invention is to provide means for connecting the main vacuum line direct to the vacuum elements on the cylinder without passing through the cylinder journal box.

Another important object of my invention resides in 2,713,823 Patented July 26, 1955 the provision of a stationary element which will automatically and in timed relation, provide a positive vacuum seal with a sliding surface of a rotary, reciprocating member.

Further objects and advantages of my invention will become apparent from the following specification and appended claims when read in conjunction with the accompanying drawings in which;

Figure 1 is a fragmentary side View, in elevation, of a press which embodies my invention;

Figure 2 is a fragmentary front elevation of that end of the impression cylinder to which my device is applied;

Figure 3 is an end view of Figure 2 as seen from the right side thereof;

Figure 4 is an enlarged front view of a preferred design of shoe, and

Figure 5 is a cross sectional view taken along line VV of Figure 4.

The novel features which my invention presents and which are illustrated in these drawings, by way of example only, as applied to a vertical printing press, will become apparent from the following description and appended claims.

Referring now to Figure l of the drawings, this press comprises a main or base frame 10 on each side of which are mounted the vertically arranged auxiliary or way frame memebrs 11. Mounted on the way frames 11 and inwardly therefrom are two gears 12 which are rotatably mounted on trunnions 13 so as to mesh with racks 14 carried by the brackets 16 which in turn support the type bed 17 for vertical reciprocation in the way frames.

turn or downward stroke.

Pins 18 are carried by the brackets 16 to which are connected the rods 19 having their free ends pivotally attached to the cranks 21 mounted on the main drive shaft 22 which is journalled for rotation in the base frame 10 of the press.

An impression cylinder 23 is rotatably mounted'in the side arms 24 of the cylinder frame 26 which is arranged to be reciprocated vertically in the way frames 11. Secured to the cylinder frame 26 are the racks 27 which are arranged to mesh with the gears 12.

From this arrangement it will be apparent that when the press is in operation the connecting rods 19 will transmit a driving force from the crankshaft 22 to the brackets 16 for reciprocating the type bed 17 in a vertical direction.

The driving force will also be transmitted through the racks 14 and gear 12 to the racks 27 for reciprocating the cylinder frame and its cylinder in a vertical direction and in an opposite sense to that of the type bed.

In the preferred embodiment, the cylinder 23 is arranged to be rotated during its upward or impression stroke and it is locked against rotation during its re- Details of the mechanism for performing these functions have not been shown because they form on part of the present invention.

When the press is in operation, the sheets to be printed are transferred to the impression cylinder while it is stationary in its position when it has reached the bottom of its stroke. Vacuum ports 28, see Figure 2, are provided in the cylinder for detecting the presence and lay of a sheet as it reaches the register guides which are preferably provided on the cylinder.

The latter is imparted rotary as well as vertical reciprocatory motion, therefore, the means used for connecting the main vacuum line from the pump 29 to the vacuum elements and ports 28 on the cylinder, must be of a kind which will permit such motion and yet provide a perfect sealing connection at the moment when vacuum is being applied to said elements.

This I preferably accomplish by means of a vacuum shoe 31 which is resiliently supported on the guard 32 by means of a flat spring 33, one end of the spring being secured to said guard by means of screws 34 while to its depending or free end is riveted said vacuum shoe.

'The shoe is preferably made of a porous, self lubricating material and is provided with a flat, ground face 36, see Figures 4 and 5, in the center of which is formed a vertically disposed, elongated groove 37 which connects with a bore 38 provided in the shoe and which extends to one edge thereof. A nipple 39 is secured in the outer end of the bore 38 and is connected by means of a flexible tube 41 to the main vacuum line 42, see Figure 3.

When the cylinder 23 is down in its sheet taking position, which is also the moment when the sheet detecting operation is effected, the groove 37 in the shoe 31 is aligned with the open end of the bore 43 provided in the journal 44 of the cylinder. The opposite end of the bore 43 is connected to a diaphragm 45 from which additional lines lead to the vacuum ports 28 of the cylinder. It will be seen, therefore, that with the cylinder in this position, the vacuum line from the pump 29 to the cylinder ports 28 is completed with the flat spring 33 maintaining the ground face 36 of the shoe in position against the ground end face of the cylinder journal 44. The vacuum in the line then effects a positive seal of the shoe against said end face.

When the cylinder moves upwardly during its impression stroke and away from the shoe 31, pressure of the spring 33 would normally cause the shoe to move to the left, as seen in Figure 2, and subsequently into the path of the cylinder journal during the down stroke of the cylinder. This movement however, is limited by the adjustable screw 46 which passes through a bore provided in the guard 32 and is threaded into the shoe 31 for adjustment. Consequently, the extent of free movement of the shoe is limited to the amount of clearance provided between the head of the screw 46 and the face of the guard 32 which clearance is determined when the cylinder is down in its sheet taking position, and which should be limited to between three to five thousandths of an inch. This clearance allows sufficient freedom of movement of the shoe to insure proper engagement thereof with the cylinder journal and yet prevents the shoe from moving too far into the path of the journal.

A set screw 47 is provided to lock the adjusting screw 4'6 in its adjusted position.

As a further safety precaution against imparting shock and vibration to the shoe in the event the screw 46 should become loose and allow the shoe to move into the path of the journal, the top edge of the face 36 is beveled as at 48, see Figure 5, which will present a sloping surface to the rounded edge of the journal and which will guide the shoe gently to its operative position as the cylinder moves downward to its sheet taking position.

It will be understood, of course, that a suitable valve will be arranged in the main vacuum line in a manner that it will automatically open when the cylinder is down in its sheet taking position and at the precise moment when the sheet detecting operation is being accomplished, and will close immediately when the cylinder starts on its upward or impression stroke.

While I have herein disclosed a preferred embodiment of my invention, I do not wish to be limited to specific details because modifications in the design and arrangement of parts will be possible without departing from the spirit of my invention and scope of the appended claims.

I claim:

1. In a printing press of the class comprising a type bed, an impression cylinder, mechanism for reciprocating said bed and cylinder vertically and in opposite directions, and means for imparting rotary motion to the cylinder during its upward stroke, the combination of vacuum controlled elements associated with said cylinder, a vacuum source remote from said cylinder for actuating said elements when the cylinder is in a predetermined position in its cycle of operation, said vacuum source normally being disconnected from said elements, and a stationary coupling member connected to said vacuum source and arranged adjacent the path followed by said cylinder having operation to intermittently engage said cylinder each time it arrives at said position to thereby couple said vacuum source with said elements whereby said elements are actuated each time the cylinder is in said predetermined position.

2. In a printing press of the class set forth, the com bination comprising, a rotary, reciprocating impression cylinder having journals formed integral therewith, an axially extending air channel in one of said journals, a series of vacuum controlled elements associated with said cylinder and having a connection with said air channel, a vacuum pump for actuating said elements, said pump being located remote from said cylinder and having a vacuum line terminating adjacent the path of said journal, and a stationary coupling device connected to the end of said vacuum line having operation to engage said journal each time the cylinder reaches a pre-determined position whereby to couple said line with said air channel momentarily to thereby actuate said elements only when the cylinder reaches said predetermined position.

3. In a printing press of the class set forth, the combination comprising a rotary, reciprocating impression cylinder having a sheet receiving position, vacuum actuated elements mounted for movement with said cylinder and having operation when actuated to detect the lay of each sheet transferred to said cylinder when it is in its sheet receiving position, a vacuum source for actuating said elements, said source being located remote from said cylinder and having a vacuum line terminating adjacent the path thereof, and stationary coupling means connected to the free end of said line and having operation to couple said line with said elements only when said cylinder is in its sheet receiving position whereby vacuum from said source is effective to actuate said elements.

4. In a printing press of the class set forth, the combination comprising a rotary impression cylinder, means for imparting reciprocating motion to said cylinder in a plane perpendicular to its axis of rotation, said cylinder having a sheet receiving position at one point only in its reciprocating cycle, a series of vacuum actuated sheet detecting elements on said cylinder for detecting the lay of each sheet presented thereto, a vacuum source for actuating said elements, said vacuum source being located remote from said cylinder and normally disconnected from said elements, and a resiliently mounted vacuum shoe having a positive connection with said vacuum source and arranged adjacent the path of said cylinder for intermittent engagement therewith whereby a momentary,

positive connection is effected between said source and said elements each time and only when the cylinder is in its sheet receiving position to thereby actuate said elements.

5. In a printing press of the class described, the combination with a rotary, vertically reciprocating sheet carrying impression cylinder having a sheet taking position at the bottom of its stroke, of a vacuum source remote from said cylinder and having a vacuum line terminating adjacent the vertical path of said cylinder, sheet detecting elements mounted on said cylinder and adapted to be actuated by vacuum from said source to detect the lay of sheets presented thereto, and a resilently mounted, relatively stationary vacuum shoe connected to the end of said vacuum line and having operation to couple said line to said elements momentarily each time the cylinder reaches the bottom of its stroke, whereby vacuum from said source is available to actuate said elements only when the cylinder is in its sheet taking position.

6. In a printing press of the class described, the combination with a rotary, vertically reciprocating sheet carrying cylinder having a sheet taking position at a predetermined point in its cycle of operation, of vacuum actuated sheet detecting elements associated with said cylinder for detecting the lay of sheets presented thereto, a vacuum source remote from said cylinder and having a vacuum line terminating adjacent the vertical path of the cylinder, a vacuum shoe connected to the end of said vacuum line and having operation to couple said line with said elements momentarily, each time the cylinder reaches its sheet taking position to thereby efiect actuation of said elements, a guard member mounted adjacent the path of said cylinder, resilient supporting means for said shoe whereby the shoe is maintained against vertical movement while being urged laterally in a direction toward the vertical path of the cylinder, and means carried by said shoe and having coaction with said guard for limiting the lateral movement of the shoe when the cylinder is removed from its sheet taking position. 

